Improvement in counter-balances for elevators



BSheets-SheetL I-I. R. PLIMPTON.

GOUNTERBALANCES FOR ELEVATORS.

No. 195,305- Patented Sept.18,11877.

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Patented Sept.18,1877.

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H. R'.- PLIMPTON.

COYUNTERBALANCES FOR ELEVATORS. 195,305.

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yHENRY R. PLIMPTON, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN COUNTER-BALANCES FOR ELEVATORS.

Speciiieation forming' part of Letters Patent No.' 195,305, dated September 18, 1877; application filed I November 19, 1875.

To all 'whom it may concern:

Be it known that I,- HENRY R. vPLIMPTON, of Boston, in the county of SuEol-k and State of Massachusetts, have invented anew and useful Improvement in Counter-Balances for Elevators, and for yother purposes, of which the following, taken in connection with the accompanying drawings, is a specification.-

' My invention relates to a variable descendving counterbalan'ce-weight, adapted to equalthe whole height of the lift; and has for its y object'the equalization of the load to be raised tothe pressure of the water at all points of the ascent, or, in other words, the application of a variable counter-balance in such a manner as to compensate for the increase of the load to be raised, which is due to the variation of the buoyant power of the water as the piston moves from its lowest to its highest position. y

It is -a well-,known fact that a solid body oating in or onl the water weighs less, or it may be raised with less' power exerted, than when suspended 4in" the atmosphere, the difference being :just-equal lto 'thei' weight of water displacedg-*hence it follows that a piston of the kindyabove described,-when im'- mersed its whole `'length in water, weighs considerably less :than when only Ahalf immersed, and ystill l less than when its loweren'd only touches the surface of the water. Owing to this fact ithas been'found that, while elevators of thisclasswork well and-economically for short lifts, they are not `economical for lifts of fty toone' hundred feet, for the reason that to raise one thousand pounds sixty feet high a power of about sixteen hundred and fifty pounds must be exerted through the Whole length of the lift.

My invention is designed to obviate this objection; and it consists in the use, in combination with an elevator-car or other Weight to be raised, operated, or moved by the direct pressure of a column of water acting upon a piston carrying the load at its upper end, and working in a vertical cylinder, of a chain or other flexible connection attached at one end to the car or piston, and passing over a pulley drum or sheave placed above the highest point to which the car ascends, and having secured to its other end a constant andinvariable weight of a capacity sufficient to nearly counterbalance the weight of the piston, car, and a length of the chain leading from said weight to the car, equal to the whole height ofthe lift of the car, said connecting-chain or other dexible connection made of such a size and weight that, as the piston ascends and the power or buoyancy of the water acting upon the pisten diminishes, and the weight of load being raised is correspondingly increased, a corresponding weight of the exible counterpoise chain shall be added to the weight ofthe constant counterbalance-weight attached to its end by a given Weight being transferred from one side of the suspension pulley or sheave to the other side thereof', and thus increasing the weight of the descending counter-balance just in proportion to the increased weight of the load. This result is accomplished by making the flexible counter-balance of a weight per foot in length proportionate to the weight of waterL displaced by every foot of movement of the piston, as will be hereainfter described.

In the drawings, Figure 1 is a front elevation of an elevator illustrating my invention. Fig. 2 is a horizontal section on line .r x on Fig. 1. Fig. 3 is a vertical section on line z z on Fig. 1, and Fig. r4 is a similar section illustrating a modification of my invention.

A is a cylinder, closed at its lower end, and provided at its upper end with a suitable stuffing-box, a, and adjustable gland b, and also provided with an inlet-passage, c, and outlet-passage d, located near its upper end or just below the stuffing-box, as shown.

The cylinder A is set in the ground in a perpendicular position entirely below the low- 4. As a means of connection between a load to be raised and a dead-weight counterpoise, a chain or other flexible connection having certain specified and defined portions of its length made of different Weights, substantially as shown 4and described, for the purposes specified.

Executed at Boston this 16th day of November, 1875.

HENRY RICHARDSON PLIMPTON.

Witnesses:

WM. P. EDWARDS, E. A. HEnmENWAY. 

